Lastly, thanks to forum member general41391, we've gotten a look at the Billboard Catalog 200 chart. This chart is a listing of albums that are too old to place on the regular album charts.

This week, Hybrid Theory placed at #57 on the list, selling 2,992 copies in the U.S. Official U.S. sales totals for the album are at 9,391,674 since its release in 2000. Meteora hit #80 on the same chart, selling 2,479 copies, bringing its total sales amount to 5,568,205 copies since 2003. The full list can be seen here

You may ask "I thought Hybrid Theory was certified diamond (10x platinum)?", and I can tell you that they were. Certifications such as gold, platinum, diamond, etc take into account the amount of albums shipped to retailers, and not an exact total of sold copies (since each store typically has copies of the album on their shelves that have not been sold). Hopefully this clears things up.

Thanks to general41391!